New users seeking access to a network have to register with the network first. In return, the network grants them a ‘lifetime’, which describes the period over which the network can be accessed by the user. In turn, users have to periodically renew their registrations with the network before their lifetime expires, if they desire to continue their access. The network has a maximum prescribed lifetime. In order to ensure that users are still present on the network, the network will also request them to periodically re-register, so that it can continue reserving resources for the users. The maximum prescribed lifetime is generally a global setting for all users.
When a large number of users are accessing the network in this manner, the processing of registration requests from these users can create a disproportionately high level of load in the network element/server responsible for processing user registrations. Since the arrivals of these user requests tends to be non-uniform, server load can peak at different times, leading to delays in granting access, or worse, loss of registration requests due to overload conditions. Furthermore, the rate of initial access registration requests is not within the control of the registration server, as initial access requests originate from outside the server.
Therefore, it would be desirable to alleviate the problem of network element/server overload when handling user registrations.